Because Streptococcus pyogenes and Staphylococcus aureus are common causes of cellulitis and erysipelas, treatment with an antistaphylococcal β-lactam is widely recommended. However, during oral treatment, serum levels of these agents are less than the minimum inhibitory concentration of many methicillin-sensitive strains of S. aureus for a significant portion of the dosing interval, and consequently, treatment is often initially given intravenously and then orally. Clindamycin is active against most strains of S. pyogenes and S. aureus and, when given orally, achieves adequate serum levels throughout the dosing interval. Treatment of cellulitis with oral clindamycin might provide better outcomes than those achieved with an antistaphylococcal β-lactam given intravenously and then orally.
Adult patients with cellulitis were enrolled in a randomized, double-blind trial that compared clindamycin 300 mg 4 times a day administered orally, with flucloxacillin 2 g every 6 hours administered intravenously, followed by flucloxacillin 500 mg 4 times a day administered orally. The patients were assessed daily while inpatients, at completion of treatment, and at 4 weeks after entry.
Forty eligible patients were randomized and completed treatment: 21 with oral clindamycin and 19 with intravenous followed by oral flucloxacillin. At the completion of treatment, 7 of 19 patients in the flucloxacillin group and 18 of 21 in the clindamycin group were considered cured and 11 of 19 in the flucloxacillin group and 3 of 21 in the clindamycin group were considered improved (P = 0.003). There were no significant differences between the 2 groups with regard to duration of treatment, duration of hospital stay, rate of relapse, or that of adverse events.
Clindamycin administered orally was at least as effective as flucloxacillin administered intravenously and then orally.